The impact of urea-induced unfolding on the redox process of immobilised cytochrome c

Monari, Stefano; Millo, Diego; Ranieri, Antonio; Rocco, Giulia Di; Zwan, Gert van der; Gooijer, C.; Peressini, Silvia; Tavagnacco, Claudio; Hildebrandt, Peter; Borsari, Marco

doi:10.1007/s00775-010-0681-7

Cited by 31 publications

(57 citation statements)

References 76 publications

(114 reference statements)

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“…A polycrystalline gold wire was used as a working electrode, a Pt sheet and a saturated calomel electrode as counter and reference electrode, respectively. The working gold electrode was functionalized as reported elsewhere [9]. CV experiments on the protein-coated electrodes were performed using a working solution containing 9 M urea, 10 mM NaClO 4 and 5 mM phosphate buffer at given by the urea-unfolded immobilized ycc and its variants was studied by gradually adding aliquots of a H 2 O 2 solution at known concentration to the above solution under argon atmosphere.…”

Section: Methodsmentioning

confidence: 99%

“…Although the role of the peroxidase activity of unfolded cytc is well established in several physiological and pathological contexts, the mechanistic details of the process and the structure of the unfolded species remain largely unknown. Previous studies showed the presence of two distinct states of surface-immobilized unfolded cytc differing mainly in the axial ligation of the heme center [9]. In particular, a native-like state is observed under mild unfolding conditions, in which the heme is still axially coordinated by Met80 and His18.…”

Section: Introductionmentioning

confidence: 96%

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A bis-histidine-ligated unfolded cytochrome c immobilized on anionic SAM shows pseudo-peroxidase activity

Ranieri

Battistuzzi

Borsari

et al. 2012

Electrochemistry Communications

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Urea-unfolded yeast iso-1-cytochrome c electrostatically adsorbed on a gold electrode coated with an anionic self-assembled monolayer yields a heme-mediated electrocatalytic reduction of H 2 O 2 (pseudo-peroxidase activity). Under the same conditions, native cytochrome c is inactive. In the unfolded protein, the Met80 heme iron ligand is replaced by a histidine residue yielding a bis-His-ligated form. H 2 O 2 electrocatalysis occurs with an efficient mechanism likely involving direct H 2 O 2 interaction with the iron(II) center and formation of a transient ferryl group. Comparison of the catalytic activity of a few urea-unfolded single and double Lys-to-Ala variants shows that the kinetic affinity of H 2 O 2 for the heme iron and k cat of the bis-His-ligated form are strongly affected by the geometry of protein adsorption, controlled by specific surface lysine residues.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

A bis-histidine-ligated unfolded cytochrome c immobilized on anionic SAM shows pseudo-peroxidase activity

Ranieri

Battistuzzi

Borsari

et al. 2012

Electrochemistry Communications

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“…According to the reported, the exposure of heme cofactor to solvent and the nature of the axial ligand seems to be the principal determinant for the magnitude of the formal potential 40,47,48. According to the reported, the exposure of heme cofactor to solvent and the nature of the axial ligand seems to be the principal determinant for the magnitude of the formal potential 40,47,48.…”

mentioning

confidence: 94%

Label-Free Surface-Enhanced Infrared Spectroelectrochemistry Studies the Interaction of Cytochrome c with Cardiolipin-Containing Membranes

Liu

Zeng

et al. 2015

J. Phys. Chem. C

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Interactions of cytochrome c (cyt c) with cardiolipin (CL)-containing membranes have been revealed to play an important role in inducing early apoptosis. In this paper, we studied the interaction of cyt c with solid-supported CL-containing lipid bilayers by a lable-free spectroelectrochemistry method. The biomimetic membrane was fabricated by fusing cardiolipin-phosphatidylcholine (CL_PC, 1:4) vesicles onto the hydrophobic surface of a preadsorbed 1-dodecanethiol (DT) on a gold electrode (CL_PC/DT/Au). The adsorption of cyt c onto the CL_PC/DT/Au was in-situ studied by cyclic voltammetry (CV) and surface-enhanced Infrared adsorption spectroscopy (SEIRAS). The electrochemistry of Cyt c/CL_PC/DT/Au exhibits the formal potential (E f ) at 0.21 V (vs. Ag/AgCl), a positive shift of 190 mV as compared to that of native cyt c adsorbed at the mercaptoundecanoic acid-modified gold Page 1 of 34 ACS Paragon Plus Environment The Journal of Physical Chemistry 2 electrode (Cyt c/MUA/Au). The potential-induced SEIRA difference spectroscopy discloses that cyt c was loosely adsorbed onto CL_PC/DT/Au in a different orientation, and underwent a new β-sheet formation relative to native cyt c adsorbed onto MUA/Au. It could be the enhanced hydration change of CL-bound cyt c upon oxidization and reduction and the different adsorption orientation that determine the positive shift in its formal potential.

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“…Based on the reported results, the magnitude of the formal potential depends mainly on exposure of heme cofactor to solvent, the nature of the axial ligand [45] and the surface charge property of absorbed film [46]. For a partially unfolded cyt c [39,47], its oxidized form always opens the heme crevice due to the change of ligand so as to have a large solvent accessibility of the heme, while its reduced form possesses a relatively compact conformation, which determines the negative shift of its formal potential relative to native cyt c. Since the structure and related heme microenvironment of cyt c treated with SiO2 NPs were changed in the oxidized form while were kept in the reduced form relative to those of native cyt c as shown in Fig.…”

Section: Seiras and Potential-induced Seira Difference Spectroscopy Smentioning

confidence: 99%

Surface-enhanced infrared absorption spectroscopy and electrochemistry reveal the impact of nanoparticles on the function of protein immobilized on mimic biointerface

Zhang

Zeng

Liu

et al. 2016

Electrochimica Acta

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Surface-enhanced infrared absorption spectroscopy and electrochemistry reveal the impact of nanoparticles on the function of protein immobilized on mimic biointerface, Electrochimica Acta http://dx. AbstractStudy of the interactions between engineered nanoparticles and biomolecules plays an important role in understanding nano-bio effect. However, most of studies focus on the interaction of protein with nanoparticle in bulk phase, the impact of nanoparticle on the function of protein immobilized on the biological interface has been ignored for a long time. In this paper, we study the effect of SiO2 NPs on electron transfer function of cytochrome c (cyt c) adsorbed onto the 11-mercaptoundecanoic acid (MUA) self-assembled monolayer (SAM) by surface-enhanced infrared absorption spectroscopy (SEIRAS) combined with electrochemistry. Our results disclose that instead of inhibiting the electron transfer, exposure of SiO2 NPs enhances the redox reversibility, electron transfer rate, and catalytic performance of adsorbed cyt c, but induces a slight negative shift in the formal potential of the adsorbed cyt c. Interaction of SiO2 NPs slightly induces the structural changes of the β-sheet in the oxidized form and the change of microenvironment surrounding them, which could further change the microenvironment and the orientation of heme, facilitating the hydration of cyt c at the oxidized state. It could be the enhanced hydration of cyt c (Fe 3+ ) and a smaller change in the total hydration from reduced to oxidized state that results in the slight negative shift in the formal potential and promotes the electron transfer capability. Besides, cyt c's slight conformational change and the disturbance to the microenvironment of heme resulting from the adsorption of SiO2 NPs could also be one of the reason that leads to the enhanced catalytic capability towards the reduction of H2O2.

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The impact of urea-induced unfolding on the redox process of immobilised cytochrome c

Cited by 31 publications

References 76 publications

A bis-histidine-ligated unfolded cytochrome c immobilized on anionic SAM shows pseudo-peroxidase activity

A bis-histidine-ligated unfolded cytochrome c immobilized on anionic SAM shows pseudo-peroxidase activity

Label-Free Surface-Enhanced Infrared Spectroelectrochemistry Studies the Interaction of Cytochrome c with Cardiolipin-Containing Membranes

Surface-enhanced infrared absorption spectroscopy and electrochemistry reveal the impact of nanoparticles on the function of protein immobilized on mimic biointerface

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